We have yet to see any of the straw hats go all out post time skip.
Zorro put on his bandana only to toy with the octopus guy in the FI arc
Sanji got into a small fight vergo and didnt even use diable jambie once or amorment haki or observational haki
luffy neg diff'ed every one he's met post time skip
And remember how they fodderized pacafistas... and how pacafistas were doing more damage at MF than DD.
So its safe to say that the monster trios power post time skip cant be judged fairly.
Its when he remembers his time on Okama Island and his body ignites in flames from rage
Logically sanji if anyone has the best chance against DD. He is hands down the fastest person there, so DD will have more trouble keeping up. And When using aforementioned Hell's memories DD's strings wont be able to reach him. Not to mention with his massive speed he has observational haki so he can avoid anything DD throws at him. Diable Jambie Ftw.
look... DD was literally screwing around at Marineford, and was one of the few people to go without getting hit. If you are basing his strength on how much damage be did then... It's a poor argument.
There's no way Doflamingo would lose to Sanji. We also do not understand his string power. As such, it's impossible to say if Hell Memories (for the person who didn't know: catching himself on fire basically) prevents his strings from working.
Law is stronger than Sanji.... and he's already aware they can't be fighting Doflamingo right now. The fact that Law, despite his OP fruit, couldn't even scratch either Fujitora or Doflamingo is proof enough of their individual powers.
Sanji is going to lose. If he wins... That basically is placing Luffy on Admiral level if not higher. That's way too much development, and means by the end of the series, Luffy would be roflstomping every single opponent that comes his way. Two years isn't enough to put Luffy from someone who couldn't handle Marineford to someone who would have stood at the pinnacle of Marineford. Being only halfway through the series.... It's too much development.
There's a reason Law said only a 30-33% chance of beating Kaidou exists. It's because they aren't admiral tiers with OP powers. It's because even with some strategy made to cripple Kaidou, and make him at his weakest point when they strike... They still have almost no chance of winning.
Luffy is currently around the upper echelon of the Schichibukai... Meaning somewhere around or below Kuma, Mihawk, and Doflamingo. Sanji can't be close go any position capable of handling that man.